FLOOD02337

• County: Statewide
• Community: State
• Stream Name: South Platte River
• Basin: South Platte
• Title: Geomorphic Assessment at Surveyed Cross-sections South Platte River
• Date: 6/1/1996
• Prepared For: UDFCD
• Prepared By: Michael Stevens
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Urban Veneer is temporary. None was seen in the 1986 investigation because that was done in
June shortly after the spring runoff. The algae and organic solids are scoured and carried away
by flows that move the bed sediment. In fact, sand is not a stable substrate for algae because
sand can move at very low flows.

FLAT BED

Because of its rather straight alignment and the nature of it sediments, the bed of the South Platte
River is relatively flat across. The thalweg is not much lower than the average bed level,
meaning there are not many pools. This difference is the thalweg depth in Fig. 6. There are only
three monitored cross sections where the difference is more than 2.5 feet, all in the Rural
reaches. This means that when the flow is low, it is very shallow.

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Cross Section Number

Figure 6.

The depth that the thalweg is below the average bed level. Values are averages
for the period of record.

BANK MOVEMENT

Bankline movement is also a concern to those living along the river and to those who have
facilities on or within the river banks. Most of the banks of the South Platte River are erodible,
being composed of gravels and sands previously deposited as bars and built up to floodplain
level, or overburden from gravel mining operations. Some banks are homogeneous and others

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